Heat oil and garlic in a medium saucepan for 30 seconds. Add fennel bulbs, salt, pepper, and fennel pollen. Cook for 5 minutes then add the water and cover. Cook for 20 minutes over low heat.
Remove fennel from pan and set aside. Turn up the heat and reduce broth to about 1/4 cup. Add butter 1 tablespoon at a time. Pour sauce over the fennel and serve.
Fennel seeds that have been finely ground can be substituted for the fennel pollen.